Two recent discoveries continue to mystify us and puzzle astronomers. Recently a cosmic gas cloud had a deadly encounter with Sagittarius A, only to pass through it. Astronomers are mystified and still fighting each other about it. From recording x-rays from two different locations, we were able to measure the speed of a black hole called NGC 1365. It was discovered to be spinning at the max speed that physics will allow, and hopefully, the speed will reveal a little about this black hole’s past.
A cosmic gas cloud named G2 almost got sucked into Sagittarius A, the black hole at the center of our galaxy. But instead of getting sucked in, it passed through Sagittarius A. No one knows whether G2 even is a gas cloud or not, but some think it is a star’s atmosphere. Astronomers suggest that it isn’t a gas cloud at all. If G2 was just a cloud of gas, it wouldn’t have enough gravitational pull to stay together because Sagittarius A is 4.3 million times heavier than our sun. This is why astronomers are confused in how G2 survived.
Whatever G2 is, they don’t think it is a gas cloud, because gas clouds wouldn’t last long in the gravitational pull of an SMBH, much less Sagittarius A. However, G2 had stayed together during the process. If G2 really is a star’s atmosphere, the star is pretty unusual. This unusual star has only about two times the sun’s mass, but surprisingly, despite its mass, it is one hundred times bigger than the sun. This star size makes sense because the current theory of its existence is that two smaller stars merged together to form it.
Another theory is that it is a gas cloud after all, with intense density. This group is led by Stefan Gillessen. When G2 got close to the black hole, it didn’t go through but passed by. They think that when it got close to the black hole, it stretched out to be the shape of a cigar. We can’t see the stretch because supposedly we are seeing its end. The cloud might have survived with enough density. Both of these theories are good, but we don’t know who is right, or even if either of these are correct.
If there is one thing that we are certain of, it is the speed at which a black hole spins is extremely fast. In fact, fully developed, they spin at the maximum speed physics can allow. The maximum speed anything can spin or travel is 84% of the speed of light. This discovery will ultimately test the theory of relativity in circumstances different from the Newtonian case. SMBHs generally rip apart stars and eat them and can change the properties of space-time around it, which will greatly test the theory of relativity.
The SMBH called NGC 1365 at the center of a nearby galaxy is very powerful and was found to be spinning at 84% of the speed of light. It is 2 million times bigger than the sun and about 2 million miles across. The discovery was made by NASA’s high-energy x-ray detectors and the European Space Agency’s low-energy, x-ray detectors. Astronomers used the x-ray data to determine NGC 1365’s speed. Using this method, we can determine the spin speed of any black hole. By knowing the speed, astronomers can find out what happens in a black hole, and find out about the past of a black hole.
Knowing the speed of a black hole can help astronomers understand how the black hole and the universe around it evolved. SMBHs have a huge effect when evolving in its host galaxy. When more stars form, they give gas to the SMBH making it get bigger, but this causes radiation. The intense heat from black hole radiation can prevent more star formation. When this happens, the black hole can’t absorb more gas, stopping the radiation. These 2 events cause the other to start or stop, pause and resume.
In conclusion, black holes are mysterious in many ways. From being unable to destroy a cosmic gas cloud to spinning faster than anything has ever spun, black holes are the most unbelievable things in the universe. They have puzzled astronomers for years and have caused them to fight amongst each other. Black holes are pushing the limits of the universe, and have already pushed the speed limit. Of all the things we know, there are still lots to find out.